278 On the Employment of Sulphate of Copper, &c. 
the effect is more remarkable. The action of alum (except as it re- 
gards quantity) is much the same as that of sulphate of copper. In 
the baker’s phrase, it makes the bread swell large. 
Sulphate of Zinc.—The results obtained from this i are incon- 
siderable, and the author is persuaded that if any supposed efficacy 
has been acess to it, it must have been confounded with ouleiee 
of co 
Rekassionsia of anaenanik —No great effect on the rising of 
bread. In the proportion of ;1, it produces a yellowish color, which 
may relieve the dark color of spoiled flour. 
» Sub-carbonate of ammonia.—No very remarkable result By 
being changed to acetate it may perhaps, in common with the car- 
bonates of potash and soda, preserve the moisture of bread fora 
loager period. 
Marine salt.—Like alum and sulphate of copper, it strengthens 
the paste, but with less power. It does not produce a bread so white 
nor so well divided a crumb, as the other salts. Bread, however;'s 
much better for the use of it, for alum and copper. give very little 
taste. Their crumb is more like that of a light cake than of .com- 
mon bread. 
A sufficient quantity of common salt. may, like alum and coppes 
serve as a substitute for leaven. 
Summary.—An experimental i inquiry into the remarkable effects 
of sulphate of copper in the process.of panification, elicits the em 
couraging fact that the presence of this venomous substance can, In 
_ the very smallest proportion, be detected by chemical analysis. 
_ Every. consumer may apply the means of determining its ons? 
venience. A drop of prussiate of potash let fall on the breat 
a few seconds, gives a rose color, even when the sulphate jg only 
svoz part of the mass, 
These researches also prove that the sulphate of copper cannot be 
introduced into bread, in very. large quantity, not even in the propor” 
tion of ;;';5 part, without i injuring its appearance, and arresting the 
fermentation of the dough. A disagreeable odor also becomes man- 
ifest as soon as the proportion of the sulphate exceeds <s'sx Patt © 
the bread. 
The author expresses the hope that the numerous experiments, 
detailed in, his memoir, will throw some additional light on the subject 
of panary fermentation—still too obscure to justify any attempt 2s 
